As progress of science and technology, various kinds of plastic pipe and aluminum-plastic compound pipe are applied in the occasions where people live and work. During the application of PVC plastic pipe, a cutting knife is usually used for cutting plastic pipes so as to make it into the length required, thus many scientists devote to develop novel cutting knife or cutter suitable for cutting plastic pipe.
The Chinese patent No. 200720109332.9 disclosed a “rotary cutting knife convenient to cut large diameter pipe”, but there are deficiencies that the cutting is laborious due to manual operation, and the cutting knife itself has a complicate structure, occupies large space, and is heavy and high-cost, therefore a further improvement is needed.
The Chinese patent No. 2007201110120.2 disclosed a “forcipate PVC pipe cutting knife with automatic knife-quitting structure”, but there are also such deficiencies, that is, the cutting is laborious due to manual operation, and the cutting knife itself has a complicate structure, and is high-cost. In particular the rollback mechanism was not so compact and effective, and therefore a further improvement is also needed.